\documentclass{article}

\usepackage[utf8]{inputenc}
\usepackage[textheight = 24cm]{geometry}
\usepackage[font = sf, justification=raggedright]{caption}
\usepackage{array}
\usepackage{hhline}
\usepackage[math]{cellspace}
\cellspacetoplimit 4pt
\cellspacebottomlimit 4pt

\begin{document}

\begin{table}
	\begin{minipage}[b]{0.35\textwidth}
		\mbox{}\par
		\caption{Cellspace solution\hfill\vspace{2.5\baselineskip}}
		\begin{tabular}[b]{ >{\bfseries}l|*{6}{| >{$}Sc <{$}}}
			0 & \textbf{1}  & \textbf{2}  & \textbf{3}  & \textbf{4}  & \textbf{5}  & \textbf{6}  \\
			\hhline{=::======}
			1 & \frac{1}{1} & \frac{1}{2} & \frac{1}{3} & \frac{1}{4} & \frac{1}{5} & \frac{1}{6} \\
			\hhline{-||------}
			2 & \frac{2}{1} & \frac{2}{2} & \frac{2}{3} & \frac{2}{4} & \frac{2}{5} & \frac{2}{6} \\
			\hhline{-||------}
			3 & \frac{3}{1} & \frac{3}{2} & \frac{3}{3} & \frac{3}{4} & \frac{3}{5} & \frac{3}{6} \\
			\hhline{-||------}
			4 & \frac{4}{1} & \frac{4}{2} & \frac{4}{3} & \frac{4}{4} & \frac{4}{5} & \frac{4}{6} \\
			\hhline{-||------}
			5 & \frac{5}{1} & \frac{5}{2} & \frac{5}{3} & \frac{5}{4} & \frac{5}{5} & \frac{5}{6} \\
			\hhline{-||------}
			6 & \frac{6}{1} & \frac{6}{2} & \frac{6}{3} & \frac{6}{4} & \frac{6}{5} & \frac{6}{6} \\
		\end{tabular}
	\end{minipage}
	\everymath{\displaystyle}
	\begin{tabular}[b]{ >{\bfseries}l|*{6}{| >{$}Sc <{$}}}
		0 & \textbf{1}  & \textbf{2}  & \textbf{3}  & \textbf{4}  & \textbf{5}  & \textbf{6}  \\
		\hhline{=::======}
		1 & \frac{1}{1} & \frac{1}{2} & \frac{1}{3} & \frac{1}{4} & \frac{1}{5} & \frac{1}{6} \\
		\hhline{-||------}
		2 & \frac{2}{1} & \frac{2}{2} & \frac{2}{3} & \frac{2}{4} & \frac{2}{5} & \frac{2}{6} \\
		\hhline{-||------}
		3 & \frac{3}{1} & \frac{3}{2} & \frac{3}{3} & \frac{3}{4} & \frac{3}{5} & \frac{3}{6} \\
		\hhline{-||------}
		4 & \frac{4}{1} & \frac{4}{2} & \frac{4}{3} & \frac{4}{4} & \frac{4}{5} & \frac{4}{6} \\
		\hhline{-||------}
		5 & \frac{5}{1} & \frac{5}{2} & \frac{5}{3} & \frac{5}{4} & \frac{5}{5} & \frac{5}{6} \\
		\hhline{-||------}
		6 & \frac{6}{1} & \frac{6}{2} & \frac{6}{3} & \frac{6}{4} & \frac{6}{5} & \frac{6}{6} \\
	\end{tabular}
\end{table}
\mbox{}
\begin{table}
	\begin{minipage}[b]{0.3\textwidth}
		\mbox{}\par
		\caption{Arraystretch solution\hfill\vspace{6pt}}
		\renewcommand{\arraystretch}{1.667}
		\begin{tabular}[b]{ >{\bfseries}l|*{6}{| >{$}c <{$}}}
			0 & \textbf{1}  & \textbf{2}  & \textbf{3}  & \textbf{4}  & \textbf{5}  & \textbf{6}  \\
			\hhline{=::======}
			1 & \frac{1}{1} & \frac{1}{2} & \frac{1}{3} & \frac{1}{4} & \frac{1}{5} & \frac{1}{6} \\
			\hhline{-||------}
			2 & \frac{2}{1} & \frac{2}{2} & \frac{2}{3} & \frac{2}{4} & \frac{2}{5} & \frac{2}{6} \\
			\hhline{-||------}
			3 & \frac{3}{1} & \frac{3}{2} & \frac{3}{3} & \frac{3}{4} & \frac{3}{5} & \frac{3}{6} \\
			\hhline{-||------}
			4 & \frac{4}{1} & \frac{4}{2} & \frac{4}{3} & \frac{4}{4} & \frac{4}{5} & \frac{4}{6} \\
			\hhline{-||------}
			5 & \frac{5}{1} & \frac{5}{2} & \frac{5}{3} & \frac{5}{4} & \frac{5}{5} & \frac{5}{6} \\
			\hhline{-||------}
			6 & \frac{6}{1} & \frac{6}{2} & \frac{6}{3} & \frac{6}{4} & \frac{6}{5} & \frac{6}{6} \\
		\end{tabular}

	\end{minipage}
\end{table}
\end{document}
